To date, chimeric chickens are made by injecting blastodermal cells or embryonic stem cells into stage X recipient embryos, but the frequency and level of chimerism is variable and unpredictable. We are developing a universal recipient that contributes minimally, so that the contribution of donor derived cells to the resulting chimeras is constantly high and predictable. In this SBIR phase I application we plan to generate and evaluate a retroviral vector for the generation of the universal recipient. High-grade chimeras would allow the production of significant amounts of biopharmaceutical proteins in a very short period of time. High-grade chimeras would also allow the production of biopharmaceutical protein when the expression of the protein interferes with the chicken's ability to reproduce. This production could be easily scaled up to production of 100 kg within 1 year.